This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A363091 #30 May 27 2023 13:14:44
%S A363091 1,3,3,4,5,9,7,9,10,15,11,13,13,21,15,16,17,30,19,20,21,33,23,28,25,
%T A363091 39,27,28,29,45,31,32,33,51,35,41,37,57,39,46,41,63,43,44,50,69,47,48,
%U A363091 49,75,51,52,53,81,55,64,57,87,59,66,61,93,70,64,65,99,67,68,69,105,71
%N A363091 Sum of the divisor complements of the refactorable unitary divisors of n.
%F A363091 a(n) = n * Sum_{d|n, tau(d)|d, gcd(d,n/d)=1} 1 / d.
%t A363091 a[n_] := n*DivisorSum[n, 1/# &, CoprimeQ[#, n/#] && Divisible[#, DivisorSigma[0, #]] &]; Array[a, 100]
%Y A363091 Cf. A034444, A336041, A363085, A363298.
%K A363091 nonn,easy
%O A363091 1,2
%A A363091 _Wesley Ivan Hurt_, May 27 2023